**Vector Speed Regulation of an Asynchronous Motor Based on Improved First-Order Linear Active Disturbance Rejection Technology**

### **Xuesong Zhou \*, Chenglong Wang \* and Youjie Ma**

Tianjin Key Laboratory for Control Theory and Application in Complicated Systems, ofTechnology,300384,China;zhaohanyu@email.tjut.edu.cn

Tianjin University Tianjin **\*** Correspondence: eeliwei@email.tjut.edu.cn (X.Z.); 183125328@stud.tjut.edu.cn (C.W.); Tel.:+86-188-3026-7211(C.W.)

Received: 8 March 2020; Accepted: 25 April 2020; Published: 1 May 2020

**Abstract:** Asynchronous motors are widely used in industry and agriculture because of their simple structure, low cost, and easy maintenance. However, due to the coupling and uncertain factors of the actual operation of the motor, a traditional controller cannot achieve a satisfactory control effect. A linear active disturbance rejection controller (LADRC), featuring good robustness and adaptability, was proposed to improve the control efficiency of a nonlinear, uncertain plant. A linear extended state observer (LESO) is the core part of a L. The accuracy of the observation of state variables and unknown disturbances is related to the control effect of the controller. The performance of a traditional LESO is not high enough, and thus an error differential is introduced by analyzing the principle of LESO to improve its observation performance. The improved LADRC applies to the vector speed control of the induction motor. Additionally, low-speed and high-speed no-load starting, sudden load, electromagnetic torque, and three-phase stator current of the induction motor was simulated using MATLAB (Developed by MathWorks in Natick, MA, USA, and dealt by MathWorks Software (Beijing) Co., Ltd. in Beijing, China). Theoretical analysis and simulation results show that the ADRC based on the improved linear expansion observer was better than the traditional linear ADRC in terms of the dynamic and static performance and robustness.

**Keywords:** asynchronous motor; linear active disturbance rejection control; error differentiation; vector control
